It is where Melonie Martin, a single mother in the suburbs of Louisiana, retired after any one of her multiple jobs. She would close the door and be inside for about 15 minutes, she told her two sons, who knew better than to disturb but not always the reason why.

This was her time.

Her time to cry.

“She worked so hard,” said Devan Walker, her youngest son who's followed her lead.

Related

It brings him to San Diego, where the Chargers outside linebacker is one of 33 rookies who will take the field Friday morning for the start of a three-day rookie minicamp. The group is composed of six draft picks, 20 undrafted rookies and seven who are here on a try-out basis.

Walker will work to extend a streak of 16 straight years an undrafted rookie has made the team's opening roster.

That word, work, wasn't foreign in his childhood home.

Walker has never seen his mother hold fewer than two jobs. At times, to support him and older brother Wilson, she worked as many as four, a range of occupations that include manager of eight internal medicine physicians to gas station janitor.

"I just didn't feel like I had to put a price on what it cost to raise a child," Martin said in a phone interview.

She still attended all her sons' games. She still assisted with their homework.

She leaned on family, friends and faith to pull it off.

At a young age, Walker began to appreciate his mother's sacrifice.

He must have been 5 or 6 years old the day he mistakenly stormed the Castle and found her there, collapsed in the corner of the room next to the closet, overcome with exhaustion.

“Devan came in and said, 'What's wrong, Mommy?'” Martin said. “I said, 'I just need to cry because crying makes me feel better.' He said, 'OK, Mommy. That's OK to cry.' He said, 'One day, I'm going to be your husband and take care of you.'”

Walker was too young to understand he couldn't be that, but as he grew older, he made certain her work ethic would run in the family.

Martin labored so her boys could attend Catholic High, a private school in Baton Rouge. Walker struggled, however, with academics there amid a bad case of procrastination.

He wanted to play college football. If he failed, he'd be out of the house at 18, fending for himself without education as a backbone.

Worse, he thought about his mother and all her long hours — she averaged two to four hours of sleep a day.

“She worked so hard for me, so it was only right for me to work hard for myself,” Walker said. “Show her that nothing she did for me was in vain. …

“I disciplined myself. Instead of taking a shower and eating first, when I first came home, the first thing I did was sit at the table and do my homework. Sweaty, dirty, smelly after practice, it didn't matter. I sat there, and I did my homework.”

Walker graduated Catholic and attended Southeastern Louisiana, a Division I school in the Football Championship Subdivision.

He earned seven starts at defensive end as a redshirt freshman.

He started eight games as a sophomore and all 11 as a junior.

In 2012, with a new coaching staff, the Lions switched from a 4-3 defense to a 3-4, so the 6-foot-3, 250-pound Walker changed positions to outside linebacker.

His mother made sure he had a personal trainer.

Walker burned off the baggage from his love-handle lineman build.

“I went from a Pillsbury Doughboy to a mini-Hulk,” said Walker, who totaled a team-high seven sacks that was actually eight. (The stat keeper missed one against South Dakota State.)

He graduated last December with a degree in industrial technology.

When Walker's mother graduated college, she gave the diploma to her mother as a tribute. With his diploma, Walker thought it only right to do the same.

Now listed at 240 pounds and coming off his finest season, Walker expected to get drafted last month. But the seven rounds passed quietly before a phone call from Chargers linebackers coach Joe Barry.

Walker believes he wouldn't be where he is today, about to step on an NFL practice field and compete for a roster spot, without his mother.

How he greets this opportunity can honor her.

“I might not be the strongest or fastest,” Walker said, “but I have what I have, and I'm a hard worker. … I definitely have a chip on my shoulder to prove to myself and everyone that I belong in this league.”